This study tested the hypothesis that during treatment of kwashiorkor (including marasmic-kwashiorkor) with infection there is a lower rate of amino acid oxidation when the dietary intake of amino acids resembles the amino acid composition of acute phase proteins (APP's). Twenty two children in Blantyre, Malawi with kwashiorkor and acute infection were fed an iso-energetic, iso-nitrogenous diet with either egg white or milk as a protein source. The whole-body amino acid oxidation rate was measured after 24 hours by determining the plasma urea rate of appearance, and whole-body protein breakdown and synthesis rates were determined from the plasma leucine rate of appearance. TNF-( concentration was shown to correlate inversely with whole-body protein breakdown and synthesis rates, and IL-6 concentration correlated directly with C-reactive protein. We conclude that by making the amino acid composition of the diet resemble that of APPS in the treatment of acute kwashiorkor, t he rate of amino acid oxidation can be decreased.